The decreasing energy resources in the world, increasing population and the energy per capita necessitates the efficient usage of limited energy sources and hence making changes in the energy production and distribution systems. With this need and taking into consideration that the energy consumption is intensified at certain hours during the day, methods such as variable energy pricing at these hours and determining the tariff according to the load of the network are used. Energy costs are tried to be decreased by designing household appliances in compliance with the systems wherein the tariff varies dynamically depending on the load, intensity of the network.
In the state of the art, Japanese patent application no JP2003111311, a structure for reducing the cost of electric energy comprising a charge information processor, a power controller, and a load power sensor is described. In this embodiment, the charge information processor calculates the price of the electric power by using the electric unit price received from the electric producer company and the electric power load data received from the load power sensor. The power controller compares the result of this calculation with the reference price prerecorded in the operation panel relating to the desired consumption of the electric household appliances connected to this structure. When the calculated value exceeds the reference value, the energy of the household appliances connected to this structure is cut off with a certain order of priority by the decision of the power controller thereby optimizing the energy cost.
In the state of the art, Japanese Patents No JP4109995 and No JP7112093, embodiments are provided for use of energy in the night hours having discounted energy tariff in order to save energy.
The object of the present invention is the realization of a household appliance with a low energy cost and that can be operated in compliance with the energy tariff.
The household appliance realized in order to attain the aim of the present invention is explicated in the claims.
In the household appliance of the present invention, the user enters the ending time of the program to be executed during the selection of the program. The household appliance comprises a control unit that guarantees completion of the selected program within the desired time limit, maintaining to execute the program in the time interval of the discounted rate as much as possible by evaluating together the clock measuring time and the data received from the sensing means detecting the discounted rate energy signals when connected to a network wherein the energy tariff changes dynamically.
The user indicates the desired end time for ending the program together with the program selection by means of a panel disposed on the household appliance. The total duration between the time of selecting the program and the desired end time is calculated by the control unit. If the program selection is made within the time interval when energy is given in the expensive tariff by the network and if there is a longer time for executing the program than is necessary for the control unit, the control unit waits for the discounted rate energy signal from the network by not starting the program right away. During this waiting period, the control unit momentarily updates how much time has passed from the time required for completing the program and the remaining time left with the data received from the clock. When the discounted rate energy signal from the energy network is detected by the sensing means, the control unit starts the program execution process.
If a discounted rate energy signal cannot be received from the network to which the household appliance of the present invention is connected until the desired end time for the program set by the user, the control unit determines the latest time for starting the program in order to end the program in the selected end time and executes the program during this time period even if it is in the expensive tariff. Accordingly, a household appliance is supplied for the user that not only guarantees the selected program to be completed at the desired end time but also the cost of energy consumption is reduced hence utilization becomes more functional.